I have a whiskey barrel planter with a Turk’s Cap and a couple Amaryllises in it. This year’s uninvited guest is what I believe to be a fungus. It’s continually popping up in multiple locations always attached to the inside of the wood just above the soil line (I searched different types of wood fungus and came up empty though). It has the color and look of slightly dirty plaster. I’ve had the planter for 4 or 5 years. First time this particular issue has popped up. In the spring, I replace lost dirt with Miracle-Gro soil and used Osmocote plant food. I probably buy different replacement dirt each spring (can’t remember) but have been using Osmocote for a few years now. I also use Natria from Bayer on the plants in spring for bugs that like to eat them. The Natria claims to also kill fungus and over the past few days I have sprayed that directly on the fungus. Doesn’t appear to be having any affect. Is there any advice/products you can recommend to help me with this issue?
Make sure the soil is well draining. Keeping the whiskey barrel lifted up from the surface it sits on is important. You can place it on a roller dolly or even set up on bricks.
Make sure the container has air circulation. Lack of air flow around the planter can result in disease or fungus issues.
Scrubbing the container at the time of soil replacement can also help. Using a mild bleach solution or vinegar solution will aide in cleaning the container.
Allow the soil to dry slightly between waterings, this will aide in controlling the fungus.
You can use a fungicide to help control the fungus growth.